1. Field of the Invention
The present invention relates to a method, system, and program for accessing from a client a control system in a server and, in particular, accessing a printing systems manager server to perform printer related operations.
2. Description of the Related Art
Network printing systems generally comprise an assemblage of different printers, client computers, servers, and other components connected over a network. A print job is assembled at a client computer and transmitted over the network to a server linked to a variety of printers. To route print jobs through a network printing system, International Business Machines Corporation (IBM) provides Printing Systems Manager (PSM) products that provide centralized and distributed management of a network printing system. A PSM server manages the flow of print jobs and ensures that a print job is routed to a printer that can handle the job. The PSM system operates in the UNIX operating system environment.** The IBM version of the PSM server utilizes the IBM AIX operating system.**
In the PSM printing environment, a systems administrator may manage a network of printers, servers, queues, and print jobs from any AIX client, which is the operating system on which the PSM operates and manages the network printing environment. PSM provides remote management of the print system throughout the network. Remote users, administrators and other clients would use a terminal emulation (TELNET) program to logon to the PSM server using the DCE protocol. The PSM client then communicates with a PSM AIX client daemon executing on the PSM server. The user communicates PSM commands, including print operations and administrative commands, such as generating print requests, track print jobs, cancel, modify, or resubmit those jobs, query printers, and reconfigure different print objects, to the PSM AIX client daemon to execute. To communicate with the PSM server, the user at the client can use either the PSM graphical user interface (GUT) or the PSM command line to monitor and configure the PSM servers, printers, and print resources. Further details of the PSM environment are described in the IBM publication “Printing Systems Manager: Overview, Version 1.2.1”, IBM document no. G544-3962-02 (IBM Copyright, 1996), which publication is incorporated herein by reference in its entirety.
The PSM system utilizes the IBM Distributed Computing Environment (DCE) to provide for secure access of PSM resources and distributed computing. A DCE administrator can create groups of users that are allowed access to printer related operations and printer objects. For instance, only members of a certain group may be allowed to print on certain printers and only specified members of a systems administrator group may perform such administrative tasks as creating, deleting, modifying or configuring print objects. Further details of how the DCE protocol is used to provide secure access of PSM resources is described in the IBM publication “Administrating IBM Printing Systems Manager for AIX Version 1.2.1,” IBM document no. S544-396402 (IBM Copyright, 1996), which publication is incorporated herein by reference in its entirety.
To login, the user must obtain a network: login context which contains the information necessary for a subject to become a client in the DCE security environment. Once logged-on, the user may interact directly with the particular proprietary PSM system through the PSM AIX client daemon. After logging in and providing a password, the DCE login facility would initialize the login context for the client wanting to access the PSM server, and authenticate and validate the login context. The client then uses the sec_login_export_context( ) API call to obtain the login context. After obtaining the login context string, the client must present this string to access any resource when operating in the PSM DCE environment. When performing an operation, the client would present the login context string to the PSM AIX client daemon. The PSM AIX client daemon then makes a call to sec_login_import_context( ) to access the client's credential's file to determine whether the client has authority to perform th requested operation. Once the client obtains the login context, the client may make calls to various PSM services, which call the export context to determine whether the client has authority to access the requested service. Details of a client logging into the host AIX system in the DCE environment are described in the description of the login facility using sec_login API in the publication “CAE Specification, DCE 1.1: Authentication and Security Services,” Document Number: C311 (Copyright The Open Group 1997), which publication is incorporated herein by reference in its entirety.
One limitation with the current system is that after logging onto the PSM host and obtaining a login context, the client must utilize the PSM AIX command line or PSM AIX GUI interface to interface with the PSM server as the client is using a Telnet program for access. Further, the client can only access the PSM server through the PSM client daemon when logged onto the PSM server. The user cannot use the client operating system and interface programs to access the PSM server. Thus, the client and PSM client daemon are restricted to operate on the same AIX host due to the nature of the DCE login facility, sec_login, to establish a login context. This environment is not truly distributed as the client must operate from within the PSM server host.
There is thus a need in the art for an improved method to allow clients to obtain a login context and access the PSM server without having to operate from within the host of the PSM server.